The First Record of Cavity Nesting in the Ogasawara Islands Honeyeater Apalopteron Familiare on Hahajima, Bonin Islands, Japan

Ornithol. Sci. 1: 153–154 (2002)

SHORT COMMUNICATION The ﬁrst record of cavity nesting in the Ogasawara Islands Honeyeater Apalopteron familiare on Hahajima, Bonin Islands, Japan

Kazuto KAWAKAMI1,# and Hiroyoshi HIGUCHI2 ORNITHOLOGICAL SCIENCE 1 Tama Forest Science Garden, Forestry and Forest Products Research Institute, Todori 1833, © The Ornithological Society Hachioji, Tokyo 193–0843, Japan of Japan 2002 2 Laboratory of Biodiversity Science, School of Agriculture and Life Sciences, The University of Tokyo, Yayoi 1–1–1, Bunkyo-ku, Tokyo 113–8657, Japan

The Ogasawara Islands Honeyeater Apalopteron relatives Phylloscopus leaf-warblers and Turdus familiare is endemic to the Bonin Islands, where it thrushes of the Japanese mainland do not (Kiyosu survives only on Hahajima in the southern part of that 1978). Similarly, the Izu Islands’ subspecies of the island group (Ornithological Society of Japan 2000); Japanese Robin Erithacus akahige tanensis and the it is classified as vulnerable by Birdlife International Ryukyu Robin E. komadori of the Japanese south- (2000). It typically builds its nests in the forks of west islands have also used cavities for nesting in branches (Yamashina 1934; Nakane 1989; Morioka (Kiyosu 1978; Higuchi, H. unpublished data), and Sakane 1978; Higuchi et al. 1993; Ueda et al. whereas their closest relative E. a. akahige of the 1993), however, in 1995 we found the first example Japanese main islands has not (Kiyosu 1978). of a nest built in a tree cavity (Fig. 1). The nest was found on May 5, 1995, in a secondary broad-leaved evergreen forest, where it was located in the trunk of a 15m-high Casuarina equisetifolia, 7.1 m above the ground. The tree cavity entrance was 20 cm high and 5 cm wide. The nest, a deep cup made of the leaf fibers of Pandanus boninensis, was the same shape as those built on the forks of branches. One juvenile was seen to leave the nest on May 13, 1995, however the male parent (identifiable by its color-rings) was observed carrying nesting material into the cavity again on June 4. The left tarsus of the female parent was mutilated on June 22 and the pair stopped breeding. A few weeks later the female dis- appeared from the territory. Although the male re- mained in the territory, it did not use the tree cavity for nesting in 1996. Species that do not usually nest in tree cavities on the mainland, sometimes use such cavities on islands; similarly, species may use cavities on islands while their close relatives on the mainland do not use them. For example, Ijima’s Leaf-Warbler Phylloscopus iji- mae, and the Izu Islands Thrush Turdus celaenops have both used cavities for nesting on the Izu Islands (Higuchi, H. unpublished data), whereas their closest

(Rceived 4 February 2002; Accepted 27 May 2002) # E-mail: [email protected] Fig. 1. The nest in a tree cavity.

153 K. KAWAKAMI and H. HIGUCHI

It is perhaps the reduction or absence of nest-site nest sites: 1. availability and occupation of natural competitors that allows insular species or subspecies nest sites. Ardea 70: 1–24. to use tree cavities for nesting in. As with the other Birdlife International (2000) Threatened birds of the insular forms already mentioned, the honeyeater may world. Lynx Editions, Barcelona. be able to use tree cavities simply because of the ab- Carlson A, Sandstrom U & Olsson K (1998) Availabil- sence of nest competitors. Birds that typically nest in ity and use of natural tree holes by cavity nesting tree cavities are absent from the Bonin Islands, birds in a Swedish deciduous forest. Ardea 86: 109– whereas on the Japanese main islands there are many 119. cavity nesters ranging in size from owls and wood- Higuchi H, Nakane M & Maru T (1993) Home range peckers to sparrows and tits. In many habitats nest and pair duration of the Bonin Islands Honeyeater Apalopteron familiare. cavities are a limited resource and cavity nesting Strix 12: 23–33. Higuchi Y (1985) List of Birds in Ogasawara Islands, species are known to compete for available cavities including Iwo Islands and Minamitorishima. Strix 3: (e.g. van Balen et al. 1982; Carlson et al. 1998). It is 73–87 (in Japanese). possible that this case of cavity nesting by the hon- Kiyosu Y (1978) The Birds of Japan I. Kodansha, eyeater, and the other examples of cavity nesting Tokyo (in Japanese). among island species mentioned above, are examples Morioka H & Sakane T (1978) Observations of the of ecological release on islands (e.g. Baker-Gabb ecology and behavior of Apalopteron familiare (Aves, 1986). Meliphagidae). Mem Nat Sci Mus 11: 169–188. We thank Hayato Chiba, Takaya Yasui, Tamotsu Nakane M (1989) Habits and ecology of Apalopteron Hayakawa, Yoshio Hoshi, Takashi Ishii, Ryuji familiare at Hahajima Island. Annu rep Ogasawara Tokiwa, Osamu Tsunashima and Seiji Tazawa for res 13: 20–29 (in Japanese). their assistance and encouragement. Ornithological Society of Japan (2000) Check-list of Japanese birds. 6th ed. Ornithological Society of REFERENCES Japan, Obihiro. Ueda K, Nagano Y & Karaki M (1993) Nest site and Baker-Gabb DJ (1986) Ecological release and behav- clutch size of Apalopteron familiare, Zosterops ioral and ecological ﬂexibility in marsh harriers on is- japonicus and Cettia diphone at Hahajima Island. lands. Emu 86: 71–81. Annu Rep Ogasawara Res 16: 18–28. (in Japanese) Balen JH van, Body CJH, van Franeker JA & Osieck Yamashina Y (1934) A natural history of Japanese birds ER (1982) Studies on hole-nesting birds in natural Vol 1: pp 462–467. Azusashobo, Tokyo (in Japanese).

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